Natural Uranium

Natural uranium (NU) refers to refined uranium with the same isotopic ratio as found in nature. It contains 0.7% uranium-235, 99.3% uranium-238, and a trace of uranium-234 by weight. In terms of the amount of radioactivity, approximately 2.2% comes from uranium-235, 48.6% uranium-238, and 49.2% uranium-234.

Natural uranium can be used to fuel both low- and high-power reactors. Historically, graphite moderated reactors and heavy water moderated reactors have been fueled with natural uranium in the pure metal (U) or uranium dioxide (UO2) ceramic forms, however experimental fuelings with uranium trioxide (UO3) and triuranium octaoxide, (U3O8) have shown promise.

The 0.72% U-235 is not sufficient to produce a self-sustaining critical chain reaction in light water reactors or nuclear weapons; these applications must use enriched uranium. In rare occasions, earlier in geologic history when U-235 was more abundant, uranium ore was found to have naturally engaged in fission, forming natural nuclear fission reactors.

During the Manhattan Project, the name Tuballoy was used to refer to natural uranium in the refined condition; this term is still in occasional use at present.

Other articles related to "uranium, natural uranium, natural":

Depleted Uranium
... Depleted uranium (DU also referred to in the past as Q-metal, depletalloy or D-38) is uranium with a lower content of the fissile isotope U-235 than natural uranium ... (Natural uranium is about 99.27% U-238, 0.72% U-235—the fissile isotope, and 0.0055% U-234) ... Most depleted uranium arises as a byproduct of the production of enriched uranium for use in nuclear reactors and in the manufacture of nuclear weapons ...
Heavy Water Reactor - Purpose of Using Heavy Water
... Natural uranium consists of a mixture of various isotopes, primarily 238U and a much smaller amount (about 0.72% by weight) of 235U ... can support a self-sustained chain reaction, but due to the low natural abundance of 235U, natural uranium cannot achieve criticality by itself ... in 235U increases to a level that permits a sustained chain reaction in the uranium as a whole ...
Peak Uranium - Uranium Supply - Breeding
... A breeder reactor produces more nuclear fuel than it consumes and thus can extend the uranium supply ... It typically turns the dominant isotope in natural uranium, uranium-238, into fissile plutonium-239 ... amount of energy to be produced per mass unit of uranium, because U-238, which constitute 99.3% of natural uranium, is not used in conventional ...
Heavy Water Reactor - Purpose of Using Heavy Water - Advantages and Disadvantages
... use of heavy water moderator is the key to the PHWR system, enabling the use of natural uranium as fuel (in the form of ceramic UO2), which means ... This means that a PHWR is not only able to "burn" natural uranium and other fuels, but tends to do so more efficiently as well ... It is also notable that the reduced energy content of natural uranium as compared to enriched uranium necessitates more frequent replacement of fuel this is normally accomplished by use of an on-power ...

Famous quotes containing the word natural:

    Chastity is a monkish and evangelical superstition, a greater foe to natural temperance even than unintellectual sensuality.
    Percy Bysshe Shelley (1792–1822)